It’s estimated that today, across the country, approximately 20 percent of Americans — 48 million people — suffer from hearing loss. That’s the highest the number has ever been, and it clues us in on a trend: On the whole, the hearing health of Americans continues to decline. Which begs the question: When did it really start to change? Did our ancestors suffer hearing problems, or did they hear better than we do today?
According to a study from researchers at New York’s Binghamton University>, early humans apparently had better hearing than both modern humans and even chimpanzees — depending on what sounds were being delivered at what frequencies.
We know early humans had the advantage of better hearing based on studies of fossils: Early human skulls that have been discovered in South Africa tell us how our ancestors used their ears. Using virtual reconstructions of the fossilized remains, researchers have studied the anatomy of the outer and middle ear of these humans and compared the anatomy with that of chimpanzees.
Based on comparisons, our early human ancestors showed shorter and wider external auditory canals with smaller tympanic membranes. The bone structure of our ancestors affected the transmission of sound to the inner ear, which means they heard things differently than we do today.
Early humans had heightened sensitivities to frequencies between 1.5 and 3.5 kHZ. That means that any hard consonant sounds — P, H, G, CH and SH — and sounds like rustling leaves, footsteps on the ground, rolling thunder, and trickling water (and more modern sounds, like vacuum cleaners and ringing telephones) would have been heightened for early humans.
On the other hand, however, modern humans do hear better in upper frequencies; the sounds of “F,” “S” and “K” are easier to hear, as well as female voices, which are generally lighter and higher.
So while it appears that early humans had an edge over modern humans in terms of hearing, it also means that our pattern of communication has changed over time. Early humans were better at hearing high frequencies than chimpanzees, but modern humans are better than early humans at hearing those sounds. It’s a hearing skill that better enables us to talk across tables and in restaurants; early humans had no such conversations — they communicated in grunts and noises across forest floors.
While we have no way of knowing what percentage of early humans might have suffered hearing loss, we hypothesize that even though it appears that, on the whole, we are at greater risk today for hearing loss than in decades before us, but our hearing patterns have also changed with us to adapt to how we live. Thanks to advancements in health and medical care, today’s humans are living longer than ever before in history. As a result, more and more people are experiencing the effects of hearing loss due to living longer lives than our ancestors.
Are you one of the 48 million modern day Americans suffering from hearing loss? Contact Associated Audiologists today to find out how our doctoral-level audiologists can help you hear and keep you tuned in to life.